The objective of the Macular Photocoagulation Study is to evaluate the efficacy of argon laser photocoagulation in the treatment of subretinal neovascularization occurring in senile macular degeneration, presumed ocular histoplasmosis, and idiopathic subretinal neovascularization. The goal for this year has to enter 36 patients with one of these three diseases, treating half of them with argon lser photocoagulation to obliterate the new vessel network and allowing the other half of the patients to follow a normal course without treatment. A comparison could then be made between the treated group and the natural history group. We now have a total of fourteen patients in the study. This total includes nine patients in the senile macular degeneration category, one patient in the presumed ocular histoplasmosis category, and four patients in the idiopathic category. Seven patients have been assigned to treatment with argon laser photocoagulation and seven patients have been assigned to no treatment.